New evidence in support of a link between Zika virus infection and an increase in the incidence of neurological syndromes in adults has come from a prospective, observational study that demonstrates the presence of the infection in both serum and cerebrospinal fluid of patients with new-onset acute neuroinflammatory disease.

In the study cohort, 29 patients were diagnosed with GBS, 7 with encephalitis, 3 with transverse myelitis, and 1 with chronic inflammatory demyelinating polyneuropathy. These numbers indicate a fourfold increase in neurological syndrome diagnoses in adults, compared with a similar time frame during 2013-2014, before the Zika outbreak in Brazil, the investigators wrote.

Overall, it appears that Zika virus is associated with the trend for the rapid increase in hospital admissions for certain neurological syndromes, Dr. da Silva and his coauthors said. In addition, “we believe that our method of matching CSF and blood serologic findings offers a substantial aid to minimize [costs and] cross-reactivity in countries with a high prevalence of other concurrent flavivirosis.”

The study cohort was enrolled at a tertiary care, academic hospital in Rio de Janeiro. The median age was 44, and 15 were women. The study was limited by selection of neurological syndromes that have previously been associated with other flaviviruses, the short study period, and the use of patients from only one hospital.

Dr. da Silva reported no financial disclosures. One author reported receiving grants from Conselho Nacional de Desenvolvimento e Pesquisa and Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro. Other study authors reported no financial disclosures.